My girlfriend said she read that you're not supposed to, but I can't find any info about it online. I'm just finishing up day four with no noticeable effects except a little constipation, and I'd like to have a beer. The lady at GNC said it flushes out all the bad stuff in my body, but takes the good bacteria with it. I know beer has yeast cultures and stuff so I don't know if this would be bad for me. Does anybody have some reliable info as to whether or not it's ok to drink alcohol while I'm on this program?